What is the worse that can happen if your iron is low ?

Fatigue and worse...: Hair loss, fatigue, and a swollen tongue can all be symptoms of low iron levels. While this would be unusual most people just get real tired from subsequent low blood counts. You should see your doctor and get tested if you have any of these symptoms. http://www.webmd.com/a-to-z-guides/iron-deficiency-anemia-topic-overview

Cause?: First of all one must find why the iron is low and treat this. Iron is essential to the body so you always want to keep your body stable and in balance to function properly

Wrong question: The effect of low iron depends on how low, how fast, and why. It also depends on the health status of the person. A 21-year old woman with low iron has probably lost blood with heavy menstrual flow. If it is low enough she will have anemia. Her symptoms depend on the cause and extent of her anemia and how fast it occurred. There are MANY other types of bleeding, chronic and acute.